SAN FRANCISCO — After years of wavering about how to handle the extreme voices populating its platform, Facebook on Thursday evicted seven of its most controversial users — many of whom are conservatives — immediately inflaming the debate about the power and accountability of large technology companies.

The social network said it had barred Alex Jones, the conspiracy theorist and founder of Infowars, from its platform, along with a handful of other extremists. Louis Farrakhan, the outspoken black nationalist minister who has frequently been criticized for his anti-Semitic remarks, was also banned. The Silicon Valley company said these users were disallowed from using Facebook and Instagram under its policies against “dangerous individuals and organizations.”

“We’ve always banned individuals or organizations that promote or engage in violence and hate, regardless of ideology,” a Facebook spokeswoman said in a statement. “The process for evaluating potential violators is extensive and it is what led us to our decision to remove these accounts today.”

Facebook’s move is one of the tech industry’s broadest actions to punish high-profile extremists at a time when social media companies are under fire for allowing hateful content and misinformation to spread on their services.

With the bans, Facebook went further than it has in the past to deal with fear- and hate-mongering on its services. The company previously preferred to focus on reducing the distribution of harmful content and removing individual posts that violate its rules, rather than banning users entirely. Last year, a Facebook official, posting from the company’s official Twitter account, said that “we just don’t think banning Pages for sharing conspiracy theories or false news is the right way to go.”

That piecemeal approach has been insufficient, with new reports of lies and hate speech surfacing on Facebook almost daily. The company is also under pressure from regulators to clean up its platform. Last week, it said it was expecting the Federal Trade Commission to fine it up to $5 billion for privacy violations.

The scrutiny has prompted Facebook to evaluate its direction. Mark Zuckerberg, the chief executive, last month said he was shifting the site away from being a public town square in favor of private communications. On Tuesday, he unveiled a redesign of Facebook’s mobile app and desktop site to focus on more private group-based communications.

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Paul Barrett, deputy director of New York University’s Stern Center for Business and Human Rights, said on Thursday that Facebook’s action of banning extremists was long overdue.

“For too long, Facebook and other social media companies have claimed not to be ‘arbiters of the truth’ that appears on their platforms,” he said. “Facebook’s newest move to remove extremists like Alex Jones and Milo Yiannopoulos from the platform is just the latest piece of evidence that this is not the case. The social media companies not only have the right, but an ethical responsibility to remove disinformation and hate speech and those who spread it from their platforms.”

Many of the users barred by Facebook had previously been prohibited on other social media services. Mr. Yiannopoulos, a former Breitbart editor and far-right media personality, was banned from Twitter in 2016 after leading a harassment campaign against the actress Leslie Jones. Laura Loomer, a right-wing provocateur, was barred by Twitter earlier this year for making Islamophobic comments about Representative Ilhan Omar, Democrat of Minnesota.

The others banned by Facebook on Thursday were Paul Joseph Watson, an Infowars contributor, and Paul Nehlen, a white nationalist who ran unsuccessfully for Congress in 2018. Infowars was also booted.

Mr. Watson said in a tweet that he was given no reason for his eviction by Facebook. “I broke none of their rules,” he said. “In an authoritarian society controlled by a handful of Silicon Valley giants, all dissent must be purged.” He also appealed to the president for help, complaining in a tweet that Facebook was “now just banning people for wrongthink,” with “no pretense of enforcing rules.”

Other banned users scrambled to steer their followers to other platforms. Ms. Loomer pointed her Instagram followers to her channel on Telegram, a messaging app. Mr. Yiannopoulos told his Instagram followers to sign up for his email newsletter.

An email to Infowars was not returned. Mr. Farrakhan, Mr. Nehlen and Ms. Loomer could not be reached.

At Facebook, the bans follow an internal discussion about its content policies, said two people with knowledge of the matter, who were not authorized to speak publicly. For the past few months, the company has discussed the policies because they either focused on banning a single account, which was too narrow, or labeling someone a purveyor of hate speech or someone who incited violence, which was overly broad and required removing all associated accounts and the content under review — including those of anyone else who was supporting the same views.

The company has stressed in the past that it continuously reviews its content policies and the ways they work — or the ways they do not work — with the way people use Facebook.

Facebook’s policy team discussed how some accounts spread dangerous content but stopped short of encouraging violence or being directly affiliated with hate groups. They also wanted to find a way to remove the accounts or pages of a “dangerous individual” without blocking others from discussing what that person was saying, the people said. So in recent months, the social network updated its policies to navigate that middle ground, they said.

Facebook then found instances of extremism by Mr. Jones and others that pushed the company to take action against them. For example, Mr. Jones last year hosted an Infowars show featuring Gavin McInnes, a far-right political commentator whom Facebook had designated as a hate figure. Mr. Yiannopoulos had also signaled praise for Mr. McInnes earlier this year.

“I’m sure they’re going to make a slippery-slope argument here,” said Joan Donovan, the director of Harvard’s Technology and Social Change Research Project, who studies online extremism. “But if this kind of removal of services is because these people are in fact using their accounts to violate terms of service, or organize networked harassment, then it’s not really about conservative speech or any form of speech.”

Many of the users barred by Facebook remain active on YouTube and other social platforms. Mr. Watson maintains an active channel on YouTube, where he has 1.6 million subscribers. Mr. Jones, who was kicked off YouTube last year, has made guest appearances on the channels of other popular users since his ban, including the podcast host Joe Rogan and Logan Paul, a YouTube creator with 19 million subscribers.

A YouTube spokeswoman declined to comment.

Tech companies’ crackdowns do not just affect the reputations of these extremist figures. They also affect their earnings, by cutting them off from large audiences who support them financially. Mr. Yiannopoulos, who was banned by Venmo and PayPal last year after using the services to harass a Jewish journalist, is reportedly in debt, and Mr. Jones — who claimed that earlier bans would strengthen him by calling attention to his cause — has seen traffic to his web properties fall sharply.

On Wednesday, a day before his latest thwarting, Mr. Jones sent an email newsletter to his fans, thanking them for “supporting the infowar” and advertising discounted dietary supplements and water filtration systems. The email pointed to an Instagram page that, as of Thursday afternoon, no longer exists.

Mike Isaac reported from San Francisco, and Kevin Roose from New York. Catie Edmondson contributed reporting from Washington.

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A version of this article appears in print on , on Page A1 of the New York edition with the headline: Facebook Bars 7 Fiery Voices, Mostly Rightist. Order Reprints | Today’s Paper | Subscribe